A system includes a host device that may be configured to initiate memory requests to a system memory. On a substrate 10 are formed magnetic layers that will become two magnetic tunnel effect elements 11, 21 as magnetoresistance effect elements. The stent may be designed according to the individual needs of particular patients. The expressed polypeptides may be substantially purified, or used in a substantially unpurified form, to be admixed with a lignocellulose source to be converted to a fermentable product such as a sugar or a mixture of sugars.